What is the electronic and molecular geometry of #"dimethyl ether"#?
2 Answers
We deal with
Explanation:
And thus, to a first approx.,
Because oxygen bears 2 lone pairs, which, as non-bonding entities, tend to lie closer to the oxygen atom, the low pairs may tend to compress
I always think about what molecule looks similar, and remember its molecular and tetrahedral geometry.
- the central oxygen is analogous to the oxygen in water if the two
#"CH"_3# fragments are replaced with#"H"# atoms. Water is bent, with a tetrahedral electron geometry, and thus has a VSEPR-predicted bond angle of#bb(109.5^@)# .
Naturally, that angle is not strictly correct (it is actually
#104.4776^@# in water), due to the lone pair crunching the molecule together, but given you are asked for the IDEAL bond angle, that's what you'll have to type in regardless.
- for one choice of carbon atom in this molecule, if you change the remaining
#"OCH"_3# to#"H"# , then it looks just like methane,#"CH"_4# . Therefore, the atom has around it a tetrahedral electron geometry, and a#bb(109.5^@)# IDEAL angle as well...
Or, if you just counted electron groups around both central atoms (
See this for a mathematical proof of the ideal tetrahedral bond angles.